Selection of Optimum Working Fluid for Organic Rankine Cycles by Exergy and Exergy-Economic Analyses
Selection of Optimum Working Fluid for Organic Rankine Cycles by Exergy and Exergy-Economic Analyses
复制标题
DOI：
10.3390/su71115362
复制
发表时间：
2015-11-01
期刊：
影响因子：
3.9
通讯作者：
Rosen, Marc A.
中科院分区：
文献类型：
--
作者：
Darvish, Kamyar;Ehyaei, Mehdi A.;Rosen, Marc A.
对利用低温热源的回热式有机朗肯循环的热力性能进行了模拟，以便于选择合适的有机工质。热力学模型用于研究有机朗肯循环（ORC）的热力学参数，如输出功率和能量效率。此外，还用火用经济分析法对电力成本率进行了分析。九种工质被认为是调查的一部分，以评估产生最高的输出功率和火用效率，在系统的限制。以（火用）效率和电费率作为系统优化的目标函数，并根据最佳操作条件对每种流体进行评估。在优化过程中，以压比和压比为自变量。发现R134 a和异丁烷表现出最高的能量和火用效率，而它们在使用其他工质的系统之间具有输出功率。当源温为120 ℃时，R134 a和异丁烷的系统的火用效率分别为19.6%和20.3%。锅炉和膨胀机的火用损失最大。对于使用R134 a作为工作流体的系统，该系统的电力成本率从0.08 USD/kWh变化到0.12 USD/kWh，这取决于燃料输入成本。
The thermodynamic performance of a regenerative organic Rankine cycle that utilizes low temperature heat sources to facilitate the selection of proper organic working fluids is simulated. Thermodynamic models are used to investigate thermodynamic parameters such as output power, and energy efficiency of the ORC (Organic Rankine Cycle). In addition, the cost rate of electricity is examined with exergo-economic analysis. Nine working fluids are considered as part of the investigation to assess which yields the highest output power and exergy efficiency, within system constraints. Exergy efficiency and cost rate of electricity are used as objective functions for system optimization, and each fluid is assessed in terms of the optimal operating condition. The degree of superheat and the pressure ratio are independent variables in the optimization. R134a and iso-butane are found to exhibit the highest energy and exergy efficiencies, while they have output powers in between the systems using other working fluids. For a source temperature was equal to 120 degrees C, the exergy efficiencies for the systems using R134a and iso-butane are observed to be 19.6% and 20.3%, respectively. The largest exergy destructions occur in the boiler and the expander. The electricity cost rates for the system vary from 0.08 USD/kWh to 0.12 USD/kWh, depending on the fuel input cost, for the system using R134a as a working fluid.